Number of nX6 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.
A201623
Number of nX6 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.
Terms
- a(0) =26a(1) =2271a(2) =256836a(3) =45733593a(4) =8368969235
External references
- oeis: A201623